(1) Field of the Invention
The present invention relates to an image display unit for use in an electrophotographic image forming apparatus such a copier, printer, facsimile machine or the like and an image forming apparatus including the display device, in particular, relating to an image display unit capable of displaying plural pages of document images in a preview representation as well as to an image forming apparatus including the same.
(2) Description of the Related Art
A conventional digital multifunctional machine including an image forming unit, scanner and the like, captures document images as image data through the scanner, stores the image data into memory and performs image recording of the image data based on the stored image data in the memory, in accordance with the conditions the user designates, such as the number of copies etc., to complete recorded matter.
In this digital multifunctional machine, if the document set on the scanner consists of multiple pages, the bundle of documents is set on the document tray of a conventionally existing automatic document feeder so that the documents are delivered one by one towards the document reader of the scanner, whereby the image of each document can be read.
In this sequential reading process of documents, some conventional apparatuses have been adapted to successively compare one document to the next and ask the operator to confirm continuation of the current job if any change of documents in image color type (color or monochrome), size, etc., was found by the comparison.
As a conventional technology, there is a disclosure of an image forming apparatus which gives a warning to ask the user to check when the color type (color or monochrome) of the output image designated by the user is different from the color type (color or monochrome) of the original images that have been actually scanned (see Patent Document 1).
As other examples, there is a technology in which if a change in document characteristics (common properties: document size, color document or monochrome document) is observed during scanning multiple documents, scanning is suspended to inform the user of that fact and ask the user to check the documents (see Patent Document 2). There is still another technology in which the document being scanned is determined to be color or monochrome so as to display a preview of the image of the document only when the document is a color one (see Patent Document 3).
Patent Document 1:
    Japanese Patent Application Laid-open 2005-189537Patent Document 2:    Japanese Patent Application Laid-open H07-23147Patent Document 3:    Japanese Patent Application Laid-open 2009-88693
However, any of the aforementioned prior art technologies are to warn the user to check the size and/or color type (color or monochrome) of the original documents, so that they were not to seek user confirmation after informing the user of the status of the documents. Therefore, the user still had to check what state the documents is in.